Cisco Catalyst 4500 Series, Software Configuration Manual

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 5 Configuring Virtual Switching Systems
In-Service Software Upgrade (ISSU) on a VSS
ISSU using the Four Command Sequence: Step 3 (acceptversion)
This step is optional. It is needed only if you wish to stop the ISSU rollback timer. Otherwise you may
proceed to the next step (
commitversion )
Cisco IOS XE software maintains an ISSU rollback timer to safeguard against an upgrade that may leave
the new active supervisor engine in a state in which communication with the standby supervisor engine
is severed. By default, this duration is 45 minutes. If the
commitversion command is not applied before
the rollback timer duration expires, the VSS reverts to the pre-upgrade version.
The acceptversion command stops the rollback timer. This means that you can maintain the system in
the current state (runversion, with the post-upgrade version running on the active supervisor engine, and
pre-upgrade image running on the standby supervisor engine) for an extended duration, and proceed to
the commitversion state only when you are satisfied with the behavior of the post-upgrade software
version.
This optional task describes how to stop the rollback timer.
This example displays the Timer before you stop it. In the following example, the “Automatic Rollback
Time” information indicates the amount of time remaining before an automatic rollback will occur.
Switch> enable
Switch# show issu rollback-timer
Rollback Process State = 00:31:09 remaining
Configured Rollback Time = 00:45:00
Switch# issu acceptversion 611 bootflash:new_image
% Rollback timer stopped. Please issue the commitversion command.
Switch# show issu rollback-timer
Rollback Process State = Not in progress
Configured Rollback Time = 00:45:00
ISSU using the Four Command Sequence: Step 4 (commitversion)
The commitversion step reloads the standby supervisor engine with the post-upgrade image.
Perform the following steps at the active supervisor engine:
Command or Action Purpose
Step 1
Switch> enable Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
Switch# issu acceptversion [ active-slot ]
[ active-image-new ]]
Halts the rollback timer and ensures the new Cisco IOS XE
ISSU process is not automatically aborted during the ISSU
process.
Enter the issu acceptversion command within the time
period specified by the rollback timer to acknowledge that
the supervisor engine has achieved connectivity to the
outside world; otherwise, the ISSU process is terminated,
when the rollback timer expires, and the system reverts to
the previous version of Cisco IOS XE software by switching
to the standby supervisor engine.
Step 3
Switch# show issu rollback-timer
Displays the amount of time left before an automatic
rollback will occur.